• # question_answer 67)   Identify the correct resonance structures of carbon dioxide from the ones given below : (a) $O-C=O$                    (b) $O=C=O$                   (c) $^{-}O\equiv C-{{O}^{+}}$                  (d) $^{-}O-C\equiv {{O}^{+}}$

(b, d) The C?O bond length is 1.15$\overset{{}^\circ }{\mathop{\text{A}}}\,$ which is less than calculated value of double bond C = O. Thus, it is believed that $C{{O}_{2}}$ molecule is a resonance hybrid. The structures (b) and (d) are the two possible resonance structures.